Breathable and foot odor-resistant water-based polyurethane synthetic leather and preparation method thereof

Abstract

The invention belongs to the technical field of synthetic leather, and specifically discloses a breathable and anti-foot odor water-based polyurethane synthetic leather and a preparation method thereof, wherein the polyurethane synthetic leather comprises a base fabric, and a water-based polyurethane foaming layer and a water-based polyurethane surface layer sequentially arranged on the base fabric, wherein the foaming slurry used in the water-based polyurethane foaming layer is composed of a cage-like polysilsesquioxane-modified water-based polyurethane emulsion, sea urchin-like zinc oxide microspheres, a water-based color paste, a foaming agent, a foam stabilizer and a filler; the surface slurry used in the water-based polyurethane surface layer is composed of a polysilsesquioxane-modified water-based polyurethane emulsion, mesoporous nano zinc oxide, a dispersant, a water-based color paste, a defoamer and a thickener. Compared with the prior art, the present invention uses zinc oxide as an anti-foot odor functional auxiliary agent and a breathable filler, has a good breathable and anti-odor effect, is low in cost, and is suitable for industrial promotion; the prepared water-based polyurethane synthetic leather has excellent antibacterial and anti-odor functions, and excellent breathability.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic leather, and particularly relates to a breathable and foot odor-proof water-based polyurethane synthetic leather and a preparation method thereof. Background Art

[0002] The soles of the feet have many sweat glands and are prone to sweating. The sweat contains a small amount of lactic acid and urea, which, combined with the large number of bacteria on the feet that multiply and decompose keratin, produces a bad smell. Natural leather is made of natural protein fibers tightly woven in three dimensions and is covered with many fine pores, which makes it breathable and less likely to cause smelly feet. Since the fur needs to be depilated and tanned during the preparation process, a large amount of wastewater is generated, causing serious pollution. Therefore, it is urgent to develop a leather material that can replace genuine leather.

[0003] Polyurethane synthetic leather has the advantages of soft gloss, soft touch, wear resistance, flex resistance, good cold resistance, easy processing, and low price. It is the most ideal substitute for natural leather and is widely used in the fields of footwear, clothing, luggage, etc. Traditional solvent-based polyurethane synthetic leather uses a wet process to replace the dimethylformamide solvent in the solvent-based polyurethane resin with water, so that the coating has continuous pores, thereby achieving moisture permeability and breathability of the synthetic leather. However, this method does not solve the problem of environmental pollution. In recent years, the production and application of solvent-based polyurethane synthetic leather have been restricted.

[0004] Waterborne polyurethane resin uses water as a dispersion medium, is environmentally friendly and non-toxic, and is a substitute for solvent-based polyurethane resin. Chinese patent CN110983811A discloses a method for preparing deodorant and breathable waterborne polyurethane shoe leather, which uses waterborne polyurethane resin slurry as a raw material, uses specially modified silicone microspheres or ultrafine silica as a moisture-absorbing and breathable auxiliary agent, and uses non-ionic organic antibacterial auxiliary agents as antibacterial and deodorizing auxiliary agents. The auxiliary agents used in this patent to achieve the breathable and deodorizing properties of the leather are expensive and costly, and are not easy to promote and apply on a large scale in industry. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a breathable and anti-foot odor water-based polyurethane synthetic leather and a preparation method thereof. The present invention introduces sea urchin-shaped zinc oxide microspheres and mesoporous nano zinc oxide as anti-foot odor functional additives and breathable fillers, and utilizes the property of zinc oxide that it can react with acids and alkalis to absorb lactic acid and urea in sweat at the same time. Zinc oxide itself and its derivatives produced after the reaction with sweat have antibacterial properties, which inhibit the generation of odor from a mechanism point of view, thereby achieving an anti-odor effect. Zinc oxide is relatively low in price, easy to obtain, less polluting, suitable for industrial promotion and application, and can effectively solve the problems in the background technology.

[0006] The present invention is achieved through the following technical solutions: A breathable and foot-odor-proof water-based polyurethane synthetic leather comprises a base fabric, and a water-based polyurethane foaming layer and a water-based polyurethane surface layer sequentially arranged on the base fabric. The foaming slurry used in the water-based polyurethane foaming layer consists of a cage-like polysilsesquioxane-modified water-based polyurethane emulsion, urchin-like zinc oxide microspheres, a water-based color paste, a foaming agent, a foam stabilizer and a filler; the surface layer slurry used in the water-based polyurethane surface layer consists of a polysilsesquioxane-modified water-based polyurethane emulsion, mesoporous nano zinc oxide, a dispersant, a water-based color paste, a defoamer and a thickener.

[0007] A further improvement of the present invention is: The base fabric is non-woven fabric.

[0008] Furthermore, the foaming slurry is composed of the following raw materials in parts by weight: 100 parts of caged polysilsesquioxane-modified aqueous polyurethane emulsion; 5-15 parts of sea urchin-shaped zinc oxide microspheres; 0.5-1 part of water-based color paste; 2-5 parts of foaming agent; 2-4 parts of foam stabilizer; Filling 5-20 servings.

[0009] Furthermore, the caged polysilsesquioxane-modified waterborne polyurethane emulsion is a polysilsesquioxane-modified polyether aromatic carboxylate-type waterborne polyurethane resin, and the sea urchin-shaped zinc oxide microspheres are prepared by a hydrothermal method and have a size of 10-20 μm.

[0010] Furthermore, the filler is a composition of kaolin and barium sulfate.

[0011] A further improvement of the present invention is: The surface slurry is composed of the following raw materials in parts by weight: 100 parts of polysilsesquioxane-modified waterborne polyurethane emulsion; Mesoporous nano zinc oxide 3-10 parts; Dispersant 0.5-2 parts; 1-5 parts of water-based color paste; 1-3 parts of defoaming agent; Thickener 0.5-1 part.

[0012] Furthermore, the polysilsesquioxane-modified waterborne polyurethane emulsion is a polysilsesquioxane-modified polyether aliphatic carboxylate-type waterborne polyurethane resin.

[0013] Furthermore, the pore size of the mesoporous nano zinc oxide is 10-20 nm.

[0014] A further improvement of the present invention is: A method for preparing breathable and foot odor-resistant water-based polyurethane synthetic leather comprises the following steps: S1, mixing the caged polysilsesquioxane-modified waterborne polyurethane emulsion, waterborne color paste, foaming agent and foam stabilizer, stirring for 20 minutes, adding sea urchin-shaped zinc oxide microspheres and fillers, and continuing to stir for 20 minutes to obtain a foaming slurry; S2, mixing the polysilsesquioxane-modified waterborne polyurethane emulsion, waterborne color paste and defoamer, stirring for 20 minutes, adding mesoporous nano zinc oxide and dispersant, continuing to stir for 20 minutes, adding thickener, stirring for 10 minutes, and obtaining waterborne polyurethane surface slurry; S3, passing the base fabric through an impregnation tank filled with a polyether type aqueous polyurethane emulsion, and then being impregnated and squeezed by a roller, and then being ironed, and then being dried at 110° C., and then being coated with the foaming slurry, and then being dried in a stepwise manner to obtain a synthetic leather base; S4, applying the surface layer slurry on the release paper through a two-roll calender, drying at 120° C., applying the second surface layer slurry on the first layer of waterborne polyurethane surface layer, laminating it with the synthetic leather base, and drying at 130° C. to obtain a semi-finished waterborne polyurethane synthetic leather; S5, separating the release paper from the semi-finished waterborne polyurethane leather to obtain a finished product of a breathable and foot-odor-resistant waterborne polyurethane synthetic leather.

[0015] Furthermore, the base fabric is a non-woven fabric. Beneficial Effects

[0016] Compared with the prior art, the present invention has the following obvious advantages: 1. The present invention introduces a POSS cage structure into the molecular chain of the waterborne polyurethane resin to form a cage-like polysilsesquioxane-modified waterborne polyurethane, so that the foaming layer and the surface layer of the prepared polyurethane synthetic leather both have intrinsic nanopores, thereby improving its air permeability and moisture permeability.

[0017] Second, the present invention introduces urchin-shaped zinc oxide microspheres into the foaming slurry and mesoporous nano zinc oxide into the surface slurry as anti-foot odor functional additives and breathable fillers. Zinc oxide can react with both acids and alkalis to absorb lactic acid and urea in sweat, and zinc oxide itself and its derivatives produced after the reaction with sweat have antibacterial properties, which inhibits the generation of odor from a mechanism perspective and achieves an anti-odor effect.

[0018] 3. The urchin-shaped zinc oxide microspheres used in the foaming slurry of the present invention have many punctures on the surface. During the compounding process with polyurethane, the steric hindrance of the punctures on the surface can effectively improve the formation rate of nano-air pores in the foaming layer; the mesoporous nano zinc oxide used in the surface slurry has a large number of regular mesoporous channels. Both of them make the present invention have a good ventilation effect and further prevent the accumulation of odor.

[0019] Fourth, the additives used in the present invention are low in price, easy to obtain, less polluting, and suitable for industrial promotion and application. DETAILED DESCRIPTION

[0020] The present invention is described in detail below in conjunction with specific embodiments. Example 1

[0021] (1) Preparation of foaming slurry for waterborne polyurethane foam layer Calculated by weight, 100 parts of caged polysilsesquioxane-modified waterborne polyurethane emulsion, 0.5 parts of waterborne color paste, 2 parts of foaming agent, and 2 parts of foam stabilizer were mixed, stirred for 20 minutes, and then 5 parts of sea urchin-shaped zinc oxide microspheres and 20 parts of filler were added, and stirring was continued for 20 minutes to obtain a foaming slurry; (2) Preparation of surface slurry for waterborne polyurethane surface layer Calculated by weight, 100 parts of polysilsesquioxane-modified waterborne polyurethane emulsion, 2 parts of waterborne color paste, and 2 parts of defoamer were mixed, stirred for 20 minutes, 10 parts of mesoporous nano zinc oxide and 2 parts of dispersant were added, and stirring was continued for 20 minutes, and 0.5 parts of thickener was added, and stirring was continued for 10 minutes to obtain a surface layer slurry; (3) Production of waterborne polyurethane synthetic leather a. Firstly, the non-woven fabric is passed through an impregnation tank filled with a polyether type aqueous polyurethane emulsion, and then impregnated and squeezed by a roller, and then ironed and dried at 110°C, and then coated with the foaming slurry, and dried by stepwise heating to obtain a synthetic leather base; b. Apply the surface layer slurry on the release paper through a two-roll calender, dry it at 120°C, then apply another layer of surface layer slurry, and further laminate it with the synthetic leather obtained in step a, dry it at 130°C, and finally separate the release paper from the leather with the laminated surface to obtain a breathable and foot odor-resistant water-based polyurethane synthetic leather product. Example 2

[0022] (1) Preparation of foaming slurry for waterborne polyurethane foam layer Calculated by weight, 100 parts of caged polysilsesquioxane-modified waterborne polyurethane emulsion, 0.5 parts of waterborne color paste, 2 parts of foaming agent, and 2 parts of foam stabilizer were mixed, stirred for 20 minutes, and then 12 parts of sea urchin-shaped zinc oxide microspheres and 20 parts of filler were added, and stirring was continued for 20 minutes to obtain a foaming slurry; (2) Preparation of surface slurry for waterborne polyurethane surface layer Calculated by weight, 100 parts of polysilsesquioxane-modified waterborne polyurethane emulsion, 2 parts of waterborne color paste, and 2 parts of defoamer were mixed, stirred for 20 minutes, 10 parts of mesoporous nano zinc oxide and 2 parts of dispersant were added, and stirring was continued for 20 minutes. Then, 0.5 parts of thickener was added and stirred for 10 minutes to obtain a surface layer slurry; (3) Production of waterborne polyurethane synthetic leather a. Firstly, the non-woven fabric is passed through an impregnation tank filled with a polyether type aqueous polyurethane emulsion, and then impregnated and squeezed by a roller, and then ironed and dried at 110°C, and then coated with the foaming slurry, and dried by stepwise heating to obtain a synthetic leather base; b. Apply the surface layer slurry on the release paper through a two-roll calender, dry it at 120°C, then apply another layer of surface layer slurry, and further laminate it with the synthetic leather obtained in step a, dry it at 130°C, and finally separate the release paper from the leather with the laminated surface to obtain a breathable and foot odor-resistant water-based polyurethane synthetic leather product. Example 3

[0023] (1) Preparation of foaming slurry for waterborne polyurethane foam layer Calculated by weight, 100 parts of caged polysilsesquioxane-modified waterborne polyurethane emulsion, 0.5 parts of waterborne color paste, 2 parts of foaming agent, and 2 parts of foam stabilizer were mixed, stirred for 20 minutes, and then 5 parts of sea urchin-shaped zinc oxide microspheres and 20 parts of filler were added, and stirring was continued for 20 minutes to obtain a foaming slurry; (2) Preparation of surface slurry for waterborne polyurethane surface layer Calculated by weight, 100 parts of polysilsesquioxane-modified waterborne polyurethane emulsion, 2 parts of waterborne color paste, and 2 parts of defoamer were mixed, stirred for 20 minutes, 3 parts of mesoporous nano zinc oxide and 1 part of dispersant were added, and stirring was continued for 20 minutes. Then, 0.5 parts of thickener was added and stirred for 10 minutes to obtain a surface layer slurry; (3) Production of waterborne polyurethane synthetic leather a. Firstly, the non-woven fabric is passed through an impregnation tank filled with a polyether type aqueous polyurethane emulsion, and then impregnated and squeezed by a roller, and then ironed and dried at 110°C, and then coated with the foaming slurry, and dried by stepwise heating to obtain a synthetic leather base; b. Apply the surface layer slurry on the release paper through a two-roll calender, dry it at 120°C, then apply another layer of surface layer slurry, and further laminate it with the synthetic leather obtained in step a, dry it at 130°C, and finally separate the release paper from the leather with the laminated surface to obtain a breathable and foot odor-resistant water-based polyurethane synthetic leather product.

[0024] The breathable and foot odor-proof waterborne polyurethane synthetic leathers prepared in Examples 1 to 3 were tested for air permeability, antibacterial rate, and flexural resistance, respectively, using the following methods: Air permeability: Test according to GB / T 5453-1997.

[0025] Antibacterial rate: Test according to the provisions of GB / T 21866-2008.

[0026] Folding fastness: Test according to the provisions of QB / T 2714-2018.

[0027] The test results are shown in Table 1: Table 1

[0028] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A breathable and anti-foot odor water-based polyurethane synthetic leather, comprising a base fabric, and a water-based polyurethane foaming layer and a water-based polyurethane surface layer sequentially arranged on the base fabric, characterized in that: The foaming slurry used in the waterborne polyurethane foam layer is composed of a waterborne polyurethane emulsion modified by cage-like polysilsesquioxane, sea urchin-like zinc oxide microspheres, a waterborne color paste, a foaming agent, a foam stabilizer and a filler; the surface layer slurry used in the waterborne polyurethane surface layer is composed of a waterborne polyurethane emulsion modified by polysilsesquioxane, mesoporous nano zinc oxide, a dispersant, a waterborne color paste, a defoamer and a thickener.

2. The breathable and foot odor-proof water-based polyurethane synthetic leather according to claim 1, characterized in that: The base fabric is non-woven fabric.

3. The breathable and foot odor-proof water-based polyurethane synthetic leather according to claim 1, characterized in that: The foaming slurry is composed of the following raw materials in parts by weight: 100 parts of caged polysilsesquioxane-modified aqueous polyurethane emulsion; 5-15 parts of sea urchin-shaped zinc oxide microspheres; 0.5-1 part of water-based color paste; 2-5 parts of foaming agent; 2-4 parts of foam stabilizer; Filling 5-20 servings.

4. The breathable and foot odor-proof water-based polyurethane synthetic leather according to claim 2, characterized in that: The caged polysilsesquioxane-modified waterborne polyurethane emulsion is a polyether aromatic carboxylate-type waterborne polyurethane resin modified by polysilsesquioxane, and the sea urchin-shaped zinc oxide microspheres are prepared by a hydrothermal method and have a size of 10-20 μm.

5. The breathable and foot odor-proof water-based polyurethane synthetic leather according to claim 2, characterized in that: The filler is a composition of kaolin and barium sulfate.

6. The breathable and foot odor-resistant water-based polyurethane synthetic leather according to claim 1, characterized in that: The surface slurry is composed of the following raw materials in parts by weight: 100 parts of polysilsesquioxane-modified waterborne polyurethane emulsion; Mesoporous nano zinc oxide 3-10 parts; Dispersant 0.5-2 parts; 1-5 parts of water-based color paste; 1-3 parts of defoaming agent; Thickener 0.5-1 part.

7. The breathable and foot odor-resistant waterborne polyurethane synthetic leather according to claim 6, characterized in that: The polysilsesquioxane-modified waterborne polyurethane emulsion is a polyether aliphatic carboxylate-type waterborne polyurethane resin modified by polysilsesquioxane.

8. The breathable and foot odor-resistant waterborne polyurethane synthetic leather according to claim 6, characterized in that: The pore size of the mesoporous nano zinc oxide is 10-20 nm.

9. The method for preparing a breathable and foot odor-resistant waterborne polyurethane synthetic leather according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing the caged polysilsesquioxane-modified waterborne polyurethane emulsion, waterborne color paste, foaming agent and foam stabilizer, stirring for 20 minutes, adding sea urchin-shaped zinc oxide microspheres and fillers, and continuing to stir for 20 minutes to obtain a foaming slurry; S2, mixing the polysilsesquioxane-modified waterborne polyurethane emulsion, waterborne color paste and defoamer, stirring for 20 minutes, adding mesoporous nano zinc oxide and dispersant, continuing to stir for 20 minutes, adding thickener, stirring for 10 minutes, and obtaining a surface layer slurry; S3, passing the base fabric through an impregnation tank filled with a polyether type aqueous polyurethane emulsion, and then being impregnated and squeezed by a roller, and then being ironed, and then being dried at 110° C., and then being coated with the foaming slurry, and then being dried in a stepwise manner to obtain a synthetic leather base; S4, applying the surface layer slurry on the release paper through a two-roll calender, drying at 120° C., applying the second surface layer slurry on the first layer of waterborne polyurethane surface layer, laminating it with the synthetic leather base, and drying at 130° C. to obtain a semi-finished waterborne polyurethane synthetic leather; S5, separating the release paper from the semi-finished waterborne polyurethane leather to obtain a finished product of a breathable and foot-odor-resistant waterborne polyurethane synthetic leather.

10. The method for preparing a breathable and foot odor-resistant waterborne polyurethane synthetic leather according to claim 9, characterized in that: The base fabric is non-woven fabric.

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